Revert "Add support for top-level uniforms in SPIR-V."

This reverts commit acba30420ce27b3464fd04fac90e822ffd0245d8.

Reason for revert: ASAN breakage on tree for
Perf-Win2019-Clang-GCE-CPU-AVX2-x86_64-(Debug|Release)-All-ASAN

 Address 0x009af69fda78 is located in stack of thread T0 at offset 1272 in frame
     #0 0x7ff75c069ddf in _asan_wrap_RtlReAllocateHeap+0x44014f (c:\b\s\w\ir\build\nanobench.exe+0x1413a9ddf)
   This frame has 35 object(s):
     [32, 104) 'body' (line 3363)
     [144, 152) 'main' (line 3365)
     [176, 184) 'ref.tmp' (line 3366)
     [208, 240) '__begin1' (line 3366)
     [272, 304) '__end1' (line 3366)
     [336, 344) 'ref.tmp27' (line 3370)
     [368, 384) 'ref.tmp31' (line 3371)
     [400, 416) 'interfaceVars' (line 3382)
     [432, 440) 'ref.tmp48' (line 3383)
     [464, 496) '__begin151' (line 3383)
     [528, 560) '__end154' (line 3383)
     [592, 596) 'id' (line 3386)
     [608, 624) 'tmp' (line 3393)
     [640, 648) 'ref.tmp114' (line 3398)
     [672, 704) '__begin1117' (line 3398)
     [736, 768) '__end1120' (line 3398)
     [800, 1008) 'uniformBuffer' (line 3405)
     [1072, 1280) 'ref.tmp159' (line 3407) <== Memory access at offset 1272 is inside this variable
     [1344, 1360) 'agg.tmp'
     [1376, 1576) 'adapter' (line 3411)
     [1648, 1848) 'ref.tmp179' (line 3413)
     [1920, 1928) 'ref.tmp191' (line 3415)
     [1952, 1960) 'ref.tmp210' (line 3421)
     [1984, 2016) '__begin1213' (line 3421)
     [2048, 2080) '__end1216' (line 3421)
     [2112, 2120) '__begin1242' (line 3427)
     [2144, 2152) '__end1247' (line 3427)
     [2176, 2192) 'entry256' (line 3427)
     [2208, 2224) 'tmp298' (line 3433)
     [2240, 2256) 'agg.tmp307'
     [2272, 2280) '__begin1365' (line 3457)
     [2304, 2312) 'ref.tmp415' (line 3469)
     [2336, 2368) '__begin1418' (line 3469)
     [2400, 2432) '__end1421' (line 3469)
     [2464, 2480) 'agg.tmp436'

Original change's description:
> Add support for top-level uniforms in SPIR-V.
>
> Previously, a uniform not wrapped in an interface block would report a
> SPIR-V error:
>
> "Variables identified with the Uniform storage class are
> used to access transparent buffer backed resources. Such variables must
> be typed as OpTypeStruct, or an array of this type..."
>
> Now, the SPIR-V code generator automatically detects such global
> variables and synthesizes a struct named _UniformBuffer to hold them.
> When these variables are accessed, an OpAccessChain instruction is added
> to grab the variable out of the struct.
>
> Change-Id: I5e852d4de01b866c291506cc8cf6eb547f097d66
> Bug: skia:11225
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/360776
> Commit-Queue: John Stiles <johnstiles@google.com>
> Reviewed-by: Brian Osman <brianosman@google.com>
> Auto-Submit: John Stiles <johnstiles@google.com>

TBR=brianosman@google.com,ethannicholas@google.com,johnstiles@google.com

Change-Id: Ib72e33dbd662a245c20bc9d45d1397454c9588a3
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:11225
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/362057
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
12 files changed